Supramolecular chiral electrochemical reduction of acetophenone with hybridization of a chiral multifarene and Au nanoparticles

A supramolecular chiral electrode was constructed by layer-by-layer assembly of gold nanoparticles (AuNPs) and an S-chiral multifarene [3,2,1] (S-CMF) on the surface of a glassy carbon electrode, which was applied for the electroreduction of acetophenone. The host-guest encapsulation of the substrate within the chiral cavity was confirmed by 1H NMR, fluorescence titration, and molecular simulation. The composite on the electrode surface was characterized by electrochemical impedance spectroscopy (EIS) and transmission electron microscopy (TEM). Optimization of the electrolysis process was performed to give a high yield of 70.9% and high enantioselectivity of 63.9% ee, which exhibited superior reactivity to the previously reported materials. The repeatability of the experiment was tested via five separate experiments and indicated consistent stability, recyclability, and reusability of the novel chiral electrode. The proposed mechanism involved supramolecular encapsulation, two single-electron transfer steps, and proton addition. The chiral electroorganic reduction was extended to more substrates to provide successful yields and enantioselectivity. (c) 2021 Elsevier Inc. All rights reserved.

Automated summary

A supramolecular chiral electrode was constructed by layer-by-layer assembly of gold nanoparticles and S-chiral multifarene on a glassy carbon electrode surface for the electroreduction of acetophenone. The optimized electrolysis process showed high yield and enantioselectivity. The experiment demonstrated the stability and recyclability of the novel chiral electrode.